The present invention relates generally to data storage media, and more specifically, to a uniquely configured data storage device protected against moisture and shock through the use of a conformal coating and a sealant.
Within the past five years, digital data storage media such as USB drives and removable flash memory cards have been widely used and increasingly popular. These types of storage media allow a consumer quick and easy access to digital files such as photo, music, video, etc. Additionally, these storage media also allow the consumer to quickly and easily save these files onto a convenient and portable storage media, thus allowing the consumer access to the files at any variety of locations on any given computer. Convenience is indeed one of the most salient features of these storage media. However, one of the other salient features of the storage media-it's portability also contributes to some of the disadvantages associated with the storage media. For example, during transport, these storage media may often be damaged by moisture (such as water) and may frequently be damaged as a result of shock, which occurs when the storage media is dropped, jarred, or otherwise physically abused.
It is extremely important to protect these storage media from the above-mentioned dangers of transport, specifically moisture and shock damage, in order to protect the digital files stored thereon. These storage media should be protected from pressure, heat, other environmental factors, and other rigors of usage. Most conventional USB drives, as well as digital non-volatile flash memory cards such as secure digital (SD) or multi-media cards (MMC), are not fully waterproof. For example, as shown in FIG. 1, a prior art USB flash drive 10 is commonly constructed using an internal circuit board 12 that includes a connector 14 mounted thereon and a plastic housing 16 that surrounds the circuit board 12 and includes an opening 18 wherethrough the connector 14 is exposed. Typically, the housing 16 is either welded or glued to the connector 14 and circuit board 12. However, because there are air pockets 20 within the device, any gaps between the connector 14 and the housing 16 or at the seams of the housing 16 may allow moisture to seep in.
Several solutions have been devised in order to protect these devices against moisture damage. In some cases, the devices use bulky rubberized protection that includes a thick rubber or polymer external housing. In other cases, a metal housing is used. Frequently, the interface between the housing 16 and the connector 14 is sealed using an O-ring 22. These solutions are often effective in protecting the circuit board 12 disposed within the devices. Nevertheless, the housing 16 of such devices, be it made of rubber, polymer, or metal, and despite the use of the O-ring 22, often loses the tight seal between the opening 18 and the connector 14 as a result of handling and aging over time. Thus, the waterproof capability of the device 10, with or without the use of the O-ring 22, may either gradually or suddenly fail.
Additionally, solutions have been advanced to protect these devices against shock and various forms of impact. Typically, the solution includes encasing the device in a very thick, often rubberized housing. While somewhat effective, the thicker walls of the housing tend to enlarge the size of the device, thus making the device bulkier and unattractive to consumers who desire a discrete, compact storage media. Additionally, if the device is to remain the same size, the internal space available for the circuit board must be decreased, which may limit the size of the circuit board and therefore limit the storage capacity of the device.
In addition to the above-mentioned solutions, these devices have also been manufactured through injection molding. In such cases, the housing is created utilizing an injection molded plastic that is formed around the circuit board. This creates a tight seal around the circuit board which results in a substantially waterproof, albeit heavy, device. However, due to the intricate and delicate design of the circuit board, the circuit board may be damaged during the injection molding process. Furthermore, after the circuit board has been enveloped in the injection molded plastic, plastic material is integrated with the circuit board and its on-board components. Thus, not only does the injection molding frequently damage crystals, passives, and flash integrated circuit (IC) packages, injection molding also makes it very difficult to repair the devices because the plastic materials are extremely difficult to separate from the circuit board without affecting the delicate interconnection or joints between the circuit board and its various components. Thus, difficulty in repair is the main drawback for an injection molded USB drive or other memory cards.
Therefore, there is a need in the art for a data storage device that will remain robust over time to offer protection against moisture and shock during the life of the device itself. In this regard, there is a need for a data storage device that resists both normal and harsh handling and aging over time, as well as other mechanical abuses such as dropping, bending, and impact, etc. Furthermore, there is a need in the art to create a waterproof and shockproof data storage device without increasing the thickness of the housing of such a device, thus maximizing the internal space for circuit boards of various sizes and storage capabilities. Additionally, there is a need in the art for a waterproof and shockproof data storage device that may be disassembled for repair without substantially damaging the circuit board. Finally, there is a need in the art for a data storage device that is not only waterproof and shockproof, but that is lightweight and compact thus providing superior waterproof and shockproof qualities without becoming heavy or bulky.